These compositions, when applied to the clitoris and to the surrounding area, have a marked stimulating and also intensifying effect in respect of female sexuality and, when applied to the penis, have a reinvigorating and retardant effect in respect of the male one.
Female sexual dysfunction (FSD) is quite a common medical condition in women, particularly during the period of the climacteric and of the menopause.
It generally relates to the condition of pain or discomfort during sexual intercourse, reduced vaginal lubrication, delay in arousal and a decrease in sexual desire with consequent difficulty in achieving orgasm, if not even anorgasmy (condition characterised by the reaching of a state of sexual arousal yet with inability to achieve orgasm).
It is by now well known that these symptoms are mostly due to the hormonal changes associated with the period of the menopause, although women also in the premenopausal period, for the most widely varying reasons (anxiety, physical and psychological stress, high blood pressure, illness, vitamin deficiencies, tranquillisers, antidepressants, etc.), can display, albeit temporarily, said symptoms.
The change in the hormonal balances associated with the menopause in particular can lead to reductions in the blood flow, thinning and dryness of the tissues in the genital and urinary system (vagina, bladder, clitoris, etc.) with unpleasant or painful sensations (burning, irritation) during sexual intercourse and, consequently, a decrease in libido, as well as difficulty or inability to reach orgasm or frigidity.
It should be remembered that orgasm, producing a sensation of intense pleasure, has an extremely important function in creating equilibrium in the relationship of the couple, making the woman feel more satisfied and consequently closer to her partner, and also the latter more gratified on a sexual and affective level.
The clitoris, containing more than 6,000 nerve endings, is the erectile and extremely vascularised organ, as well as the most sensitive part of the female body. When stimulated, its nerve endings activate muscle contractions which in turn cause the intense sensation of reaching orgasm. It is by now known to medical science that orgasm, thanks to its ability to increase the levels of oxytocin and to release endorphins, improves the mood, produces a condition of general relaxation and can have beneficial effects on sleep. Moreover it is now established that it burns a considerable quantity of calories and has a positive influence on the functioning of the cardiovascular system, thus contributing to reaching a general state of psychological and physical well-being.
The decline in sexual desire or the inability to reach orgasm are problems found more easily in women than in men.
In men however there are reports of a certain frequency, in addition to the problems due to erectile deficiency of the penis (and therefore to a lack of flow of blood in the corpora cavernosa and in the glans), also of those relating to premature ejaculation, attempts at remedying which have been made with so-called “cooling” or retardant or vasoconstrictor topical preparations, containing, for example, menthol or camphor or benzocaine and similar, all having in fact a slightly anaesthetic effect, i.e. capable of reducing the sensitivity of the glans.
This unfortunately, in some cases, can, in the long term, cause the effect of reducing the supply of blood in the corpora cavernosa and in the glans, thus causing a consequent erectile deficiency of the sexual organ.
Numerous preparations and compositions for topical use for treating female sexual dysfunction (FSD) have been described in the art and are found on the market, mostly based on direct vasodilator agents such as, for example, prostaglandin, papaverine, hydralazine, sodium nitroprusside, phenoxybenzamine, phentolamine, vasoactive neuropeptides, etc.
Similarly described and present on the market are compositions with a base of esters of nicotinic acid such as methyl nicotinate or benzyl nicotinate, also used as direct vasodilator agents, often in association with menthol for moderating the excessive rubefacient effect and the sensation of burning caused by these esters.
However, since menthol is a known vasoconstrictor (see for example the article “Effect of topical menthol on ipsilateral and contralateral superficial blood flow following about of maximum voluntary muscle contraction”, IJSPT, Vol. 6, No. 2, June 2011, p. 83), its application on human skin reduces the flow of blood in the part treated topically and the consequent strong sensation of coldness which it causes (also at low concentrations) is the disadvantage associated with compositions known in the art to described hitherto and intended for topical use for stimulating the female and/or male sexual response.
The disadvantage associated with the vasodilator agents used to date in these formulations for the stimulation of the female and/or male sexual response is therefore that of entailing an unpleasant rubefacient and itching effect for which attempts are made to attenuate by introducing other compounds, such as in fact menthol.
It is in fact known that the vasodilator substances indicated above, which boast beneficial effects on the stimulation of the female and male sexual response, can cause in some cases also negative effects such as reddening, erythema and oedema at times with itching, burning, irritations, excessive sensation of heat or cold, etc., also when present in the preparation at very low concentrations, for example in the order of 0.05-0.2%.
In particular methyl nicotinate can in some cases be highly irritating to the skin even at concentrations equal to 0.00137-0.003% as indicated in the publication “Risk profile, Methyl nicotinate MN” of the Norwegian Food Safety Authority which in turn reports information on the toxic and local irritating effects indicated in “Monograph of methyl nicotinate”-section 2.2 of the Council of Europe, 2008.
This low concentration of use of methyl nicotinate (generally below 0.1%) explains the reason why it appears very often as last ingredient or among the last INCI ingredients in many topical compositions.
There are also other types of compositions for topical use intended for the same application of those described above but without a direct vasodilator, which make use of L-arginine which in itself is not a direct vasodilator but simply the precursor of a vasodilator compound (NO: nitric oxide).
Since the L-arginine (or its esters) can notoriously (see for example U.S. Pat. No. 7,128,930) give rise to the formation of peroxides and specifically peroxynitrites, these compositions can also cause negative effects and have necessarily to contain antioxidant substances in order to moderate and/or prevent, at least partially, the damage caused to tissues by the peroxides which can be generated by the L-arginine itself.
U.S. Pat. No. 6,322,493 describes an applicator of a stimulating composition for the clitoris based on L-arginine used from 1 to 10% in combination with 0.5-5% menthol which acts as vehicle for facilitating and promoting the absorption of L-arginine through the mucous membranes.
It is therefore highly desirable to have available compositions intended for stimulation of the female and/or male sexual response which do not exhibit the disadvantageous phenomena of a strong sensation of cold, cooling and/or decrease in the flow of blood associated with the use of menthol nor the effects of reddening, itchy oedema, sensation of burning, irritations, reddening or=hyperaemising effect associated with the use of “aggressive” vasodilators such as for example the common aforementioned methyl nicotinate.
The use of menthyl nicotinate is known in cosmetic compositions for the treatment of the hair and of the skin: however as far as the Applicant is aware the use of menthyl nicotinate as stimulating agent for treating female sexual dysfunction (FSD) and/or as intensifier of the female and/or male sexual response is not known.
Even if included among the INCI ingredients of an advertising web page relating to the stimulating cream “Fem Power” of the company Sarati (Reach Medical, Inc.: “Fem Power”, 31 May 2012, Retrieved from the Internet: www.intimatehealth.com/Fempower.htm [retrieved on 2014-02-14]), the Applicant has found that menthyl nicotinate is not really contained in said cream and that its mention among the ingredients listed on the aforesaid web page is instead a printing error of the term “methyl nicotinate”, as shown by the actual INCI composition given on the tube of said cream purchased by the Applicant, the photo whereof is attached to the present Application (FIG. 1).
Moreover this “Fem Power” cream contains, in addition to the methyl nicotinate, also L-arginine among the active ingredients and therefore also has the disadvantage of generating peroxides which could cause damage to the tissues as reported above.